대한민국 해병대 서북도서 무인 수륙양용 정찰차량(AAV-UGV) 갯벌·모래사장 침하(Sinkage) 및 1,000Hz 0-Alloc C# 베카메카닉스(Terramechanics) 가변 접지압 궤도 토크 제어 엔진

using System;
using System.Runtime.CompilerServices;

namespace ZeliDesk.Defense.Marines.AmphibiousUgv
{
    public readonly record struct TerrainSensoryData(
        float VehicleSpeedMps,
        float LeftSprocketRps,
        float RightSprocketRps,
        float PitchAngleDeg,
        float MudMoistureRatio, // 0.0 ~ 1.0 (갯벌 함수율)
        float VerticalLoadKg
    );

    public ref struct TrackTorqueDistribution
    {
        public float LeftMotorTorqueNm;
        public float RightMotorTorqueNm;
        public float LeftSlipRatio;
        public float RightSlipRatio;
        public bool SinkageHazardDetected;
    }

    public static class MarinesAavTerramechanicsCore
    {
        private const float SprocketRadiusMeters = 0.28f;
        private const float TargetOptimalSlip = 0.18f;
        private const float MaxMotorTorqueNm = 450.0f;

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public static void RegulateTrackTorque(
            ref readonly TerrainSensoryData sensory,
            ref TrackTorqueDistribution output)
        {
            // 1. 좌우 궤도 선속도 및 슬립률 산출
            float vLinear = Math.Max(sensory.VehicleSpeedMps, 0.05f);
            float vLeftTrack = sensory.LeftSprocketRps * 2.0f * (float)Math.PI * SprocketRadiusMeters;
            float vRightTrack = sensory.RightSprocketRps * 2.0f * (float)Math.PI * SprocketRadiusMeters;

            float slipLeft = Math.Clamp((vLeftTrack - vLinear) / Math.Max(vLeftTrack, 0.1f), 0.0f, 1.0f);
            float slipRight = Math.Clamp((vRightTrack - vLinear) / Math.Max(vRightTrack, 0.1f), 0.0f, 1.0f);
            output.LeftSlipRatio = slipLeft;
            output.RightSlipRatio = slipRight;

            // 2. 갯벌 함수율에 따른 최대 허용 전단 마찰 토크 역산
            float soilStrengthFactor = Math.Max(1.0f - (sensory.MudMoistureRatio * 0.75f), 0.25f);
            float baseTorqueLimit = MaxMotorTorqueNm * soilStrengthFactor;

            // 3. 과도 슬립 방지 토크 클램핑 (1,000Hz 실시간 적응)
            float leftTorque = baseTorqueLimit;
            if (slipLeft > TargetOptimalSlip)
            {
                float excess = slipLeft - TargetOptimalSlip;
                leftTorque *= (float)Math.Exp(-excess * 4.0f);
            }

            float rightTorque = baseTorqueLimit;
            if (slipRight > TargetOptimalSlip)
            {
                float excess = slipRight - TargetOptimalSlip;
                rightTorque *= (float)Math.Exp(-excess * 4.0f);
            }

            output.LeftMotorTorqueNm = leftTorque;
            output.RightMotorTorqueNm = rightTorque;
            output.SinkageHazardDetected = slipLeft > 0.35f || slipRight > 0.35f;
        }
    }
}